Method and apparatus for bias crosslaying threads

ABSTRACT

A method and apparatus for forming a nonwoven web including bias crosslaid threads is disclosed in which a divergent carrier reach is formed by a pair of endless helical coil springs. The threads are wound around a narrow portion of the diverging carrier, which widens as it advances to form a broad nonwoven web. After being stabilized relative to one another the threads are then cut from the carrier.

United States Patent [72] Inventor William H. Burger Neenali, Wis.

[21] Appl. No. 826,576

[22] Filed May 21, 1969 Nov. 16, 1971 Kimberly-Clark Corporation Neenah, Wis.

[45] Patented [73] Assignee [54] METHOD AND APPARATUS FOR BIAS CROSSLAYING THREADS 12 Claims, 4 Drawing Figs.

Primary Examiner-Benjamin A. Borchelt Assistant Examiner-J. J. Devitt Attorney-Wolfe, Hubbard, Leydig, Voit & Osann, Ltd.

ABSTRACT: A method and apparatus for fon'ning a non- [52] US. Cl 156/ 181, woven web including bias crosslaid threads is disclosed in 156/440, 156/441 which a divergent carrier reach is formed by a pair of endless [51] lnt.Cl D04h 3/05, helical coil springs. The threads are wound around a narrow B65n 54/22 portion of the diverging carrier, which widens as it advances to [50] Field of Search 156/440, form a broad nonwoven web. After being stabilized relative to one another the threads are then cut from the carrier.

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' MUM?- mm W IIIII o i u m mwm METHOD AND APPARATUS FOR BIAS CROSSLAYING THREADS DESCRIPTION OF THE INVENTION This invention relates to a method and apparatus for forming nonwoven webs, and more particularly concerns a method and apparatus for bias crosslaying a plurality of thread around an advancing web carrier.

A principal object of the present invention is to provide a thread crosslaying apparatus with which a relatively broad nonwoven web may be formed by a machine having a relatively small spinner ring or other apparatus for winding individual threads around an advancing carrier. It is particularly intended to provide a means by which the formed web may be of greater width than the diameter of the spinner ring itself through which the web carrier must pass.

A further object is to provide a machine which reduces or eliminates large changes in the velocity of individual threads as they are wound around the advancing carrier, thus easing the problem of abrupt starting and stopping of thread movement and widely fluctuating thread tension as the spinner ring passes from one side of the carrier to the next.

The invention further provides for positive spacing of individual threads in the web, while providing a controlled degree of freedom in the carrier for accommodating flexing of the web during the forming process.

Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which:

FIG. I is a schematic plan view of a web-forming machine exemplifying the present invention;

FIG. 2 is a side elevation of the apparatus of FIG. 1;

FIG. 3 is an enlarged portion of the helical spring carrier showing wound strands in position; and

FIG. 4 is an enlarged side elevation of the split intermediate guide roller means used to support the web carrier.

While the invention is described in connection with a particular preferred embodiment and method of operation, it will be understood that the invention is not so limited, but on the contrary is also applicable to other web-forming apparatus in which a broad web is to be formed with a winding apparatus of limited dimensions, and in which abrupt speed changes in the movement of each individual thread must be minimized for proper operation.

Turning first to FIG. 1, there is shown in plan vie an exemplary web-forming apparatus including a spinner ring 10 for laying individual threads I 1 onto a web carrier formed from a pair of endless helical springs 12. The spinner ring 10 is of conventional design, having individual spools or cones I3 from which the threads 11 unwind through an annular array of openings in a serving ring 14. It will be understood that the spinner ring 10 is joumaled by suitable bearings (not shown) for rotation about an axis indicated at x which extends centrally through an annular opening 15 in the ring. A drive motor 16, which is preferably of the variable speed type, is provided for rotating the ring through a suitable ring gear 17 or the like.

As a principal feature of the invention, a web I8 of bias crosslaid threads 11 is formed which is considerably wider than the central opening 15 in the spinner n'ng I through which the carrier springs 12 must pass. This is accomplished by supporting the carrier springs 12 in a manner which causes them to diverge as they leave the spinner ring 10, carrying with them the web of bias crosslaid threads 11. For this purpose, guide means are provided including first guide pulleys 19 located ahead of the spinner ring and positioned to guide the carrier springs 12 through the opening in the center of the ring. A second pair of guide pulleys 20 are provided at the end of the divergent reach of the carrier springs 12 to determine the width of the web 18 thus formed. At this point the carrier springs 12 are supported for parallel movement, carrying the web I8 through further processes, such as the application of adhesive and other materials (not shown) to be supported by the web, with the end of the carrier flight being determined by a pair of supplemental guide pulleys 21. Between the guide pulleys 20 and 21 means are provided for stabilizing the threads 11 in the web 18 relative to one another in order to sustain the web. In the illustrated embodiment the stabilizing means takes the form of a pair of heated calender rolls 22 which bond the threads 11 together to form the nonwoven web 18.

After the threads 11 are bonded or otherwise anchored to one another slitter means are provided for detaching the web 18 from the carrier springs 12. In the exemplary embodiment, the edges of the web 18 are slit by knife-edged rollers 23. Upon leaving the guide pulleys 21, the carrier springs 12 return to the first guide pulleys 19 by way of pulleys 24 which are driven by suitable motors 25 to advance the carrier springs.

In carrying out the invention, the intermediate guide pulleys 20 are split into two independently supported halves (FIG. 4) to allow the individual threads 11 of the web 18 to extend therebetween. Each half of the roller 20 is furnished with a grooved peripheral portion 26 which cooperate to form a notch for receiving the spring carrier 12 when the roller halves are positioned opposite one another. The roller halves are also preferably disposed in inwardly diverging relation to facilitate passage of the threads ll therebetween while also supporting the carrier springs 12 in the cooperating grooves 26.

By utilizing the divergent carrier springs 12 as positioned between the first guide pulleys l9 and the second guide pulleys 20, the web 18 thus formed is progressively drawn apart and widened as it leaves the spinner ring I0. This has the advantage of allowing the spinner ring 10 to be made of relatively small diameter, thereby simplifying the construction of this element, and reducing the overall size of the web-forming apparatus. In addition, the relatively small width of the carrier as it passes through the spinner ring 10 reduces the magnitude of variations in thread velocity and tension as the threads 11 are drawn from their spools 13. As the web diverges, the individual threads II are pulled through the loops of the carrier springs 12 and this relatively uniform velocity component is added to the winding motion of the spinner ring 10. As a result, the threads unwind from their spools I3 at a more uniform rate, decreasing the likelihood of either breaking the threads or improperly positioning the threads in the carrier springs 12.

As an additional advantage, the carrier springs 12 are essentially free between the first guide pulleys 19 an the intermediate pulleys 20, thereby allowing them to flex and accommodate strain and fluctuations in thread tension as the web is expanded. It is a further feature of the invention, that the guide pulleys 20 and 2I are adjustably mounted so that the width of the web 18 may be varied, as shown in phantom lines in FIG. I. The threads 11 are positioned at predetermined spaced intervals in loops of the carrier spring I2, according to the web angle desired, and the number of strands per unit of web length, these parameters being governed by: the relative speed of the ring 10 and the springs I2, the number of threads I1 fed from the ring and the number of spring convolutions per unit length.

By decreasing the speed of the disc relative to the carrier springs, for example, it is possible to lay a thread in every other or every third or fourth spring convolution. This not only alters the number of threads per inch but also alters the bias angle of the crosslaid threads. Conversely, by decreasing the number of threads served from the ring while increasing the rotational speed of the ring relative to the carrier springs the number of threads per inch can be decreased while maintaining the same bias angle as before. In either case, however, it will be appreciated that while the number of threads per inch in the diverging web portion and in the parallel web portion are essentially equal, the relative bias angle of the threads decreases as the web widens in the diverging web portion. Once the web enters the parallel portion there is essentially no relative movement between the threads and the carrier springs and the threads should be stabilized by bonding or otherwise anchored relative to one another before being slit from the carrier springs.

I claim as my invention:

1. Apparatus for making a nonwoven web comprising, in combination, a pair of endless helical springs, guide means for supporting the springs to define a diverging web carrier having an increasing width in an advancing direction, drive means for moving the springs in the advancing direction, and a rotatable spinner ring means for winding web-forming threads around the advancing and diverging springs upstream of at least the principal portion of the divergent reach of the carrier springs such that the threads are oriented at an angle approaching a right angle to the direction of the springs as they are placed on the springs, thereby enabling the accurate placement of the threads and openings between convolutions of the springs, the spinner ring means having a central opening through which the springs pass in the advancing direction.

2. Apparatus as defined in claim 1 in which the diameter of the opening of the rotatable spinner ring is less than the width of the downstream end of the divergent reach of the carrier springs.

3. Apparatus as defined in claim 1 in which the spinner ring carries a plurality of thread supply cones and means defining an annular array of serving eyes through which threads from respective ones of the cones are fed as the ring is rotated. 4. Apparatus as defined in claim 1 in which the guide means include a first pair of closely spaced pulleys upstream of the thread-laying means and a second pair of widely spaced pulleys at the end of the divergent reach of the carrier springs.

5. Apparatus as defined in claim 4 in which each of said second pair of pulleys includes a pair of individually supported roller halves defining a split notch for receiving and guiding the carrier spring without obstructing the passage of the web therebetween.

6. Apparatus as defined in claim 5 in which each pair of roller halves are disposed in inwardly diverging relation and each half is formed with a complementary peripheral groove in which the carrier spring is received and guided.

7. Apparatus as defined in claim 4 including supplemental guide means disposed downstream of the second pair of pulleys for supporting the carrier springs in a parallel reach following the divergent reach.

8. Apparatus as defined in claim 6 including means located intermediate the parallel reach portion of the carrier springs for bonding the threads together to form a nonwoven web.

9. Apparatus as defined in claim 8 including thread-severing means for detaching the formed web from the carrier springs at the end of the parallel carrier reach.

10. Apparatus as define in claim 1 in which the guide means are adjustably mounted for varying the width of the web thus formed.

1 l. A method of making a nonwoven web including bias laid thread components comprising the steps of:

advancing a pair of helical springs around continuous paths which together define diverging spring reaches, parallel spring reaches and return spring reaches;

rotating a centrally apertured serving ring around the advancing springs upstream of at least the principal portion of the diverging spring reach;

laying threads fed from supply cones carried on the serving ring around the advancing and diverging springs;

bonding the threads into a sustainable nonwoven web between the parallel spring reaches; and,

severing the threads from the springs in advance of the return spring reaches.

12. A method of making a nonwoven web including bias laid thread components comprising the steps of:

advancing a pair of closely spaced helical springs through a centrally located aperture in a serving ring and thereafter guiding the springs along diverging paths;

rotating the serving ring around the diverging springs to lay threads fed from supply cones carried on the ring around the springs;

drawing the threads from their respective supply cones by guiding the springs along said diverging paths;

guiding the springs along parallel paths to terminate relative movement between the threads and springs;

anchoring the threads relative to one another to form a nonwoven web; and,

severing the threads from the springs. 

2. Apparatus as defined in claim 1 in which the diameter of the opening of the rotatable spinner ring is less than the width of the downstream end of the divergent reach of the carrier springs.
 3. Apparatus as defined in claim 1 in which the spinner ring carries a plurality of thread supply cones and means defining an annular array of serving eyes through which threads from respective ones of the cones are fed as the ring is rotated.
 4. Apparatus as defined in claim 1 in which the guide means include a first pair of closely spaced pulleys upstream of the thread-laying means and a second pair of widely spaced pulleys at the end of the divergent reach of the carrier springs.
 5. Apparatus as defined in claim 4 in which each of said second pair of pulleys includes a pair of individually supported roller halves defining a split notch for receiving and guiding the carrier spring without obstructing the passage of the web therebetween.
 6. Apparatus as defined in claim 5 in which each pair of roller halves are disposed in inwardly diverging relation and each half is formed with a complementary peripheral groove in which the carrier spring is received and guided.
 7. Apparatus as defined in claim 4 including supplemental guide means disposed downstream of the second pair of pulleys for supporting the carrier springs in a parallel reach following the divergent reach.
 8. Apparatus as defined in claim 6 including means located intermediate the parallel reach portion of the carrier springs for bonding the threads together to form a nonwoven web.
 9. Apparatus as defined in claim 8 including thread-severing means for detaching the formed web from the carrier springs at the end of the parallel carrier reach.
 10. Apparatus as define in claim 1 in which the guide means are adjustably mounted for varying the width of the web thus fOrmed.
 11. A method of making a nonwoven web including bias laid thread components comprising the steps of: advancing a pair of helical springs around continuous paths which together define diverging spring reaches, parallel spring reaches and return spring reaches; rotating a centrally apertured serving ring around the advancing springs upstream of at least the principal portion of the diverging spring reach; laying threads fed from supply cones carried on the serving ring around the advancing and diverging springs; bonding the threads into a sustainable nonwoven web between the parallel spring reaches; and, severing the threads from the springs in advance of the return spring reaches.
 12. A method of making a nonwoven web including bias laid thread components comprising the steps of: advancing a pair of closely spaced helical springs through a centrally located aperture in a serving ring and thereafter guiding the springs along diverging paths; rotating the serving ring around the diverging springs to lay threads fed from supply cones carried on the ring around the springs; drawing the threads from their respective supply cones by guiding the springs along said diverging paths; guiding the springs along parallel paths to terminate relative movement between the threads and springs; anchoring the threads relative to one another to form a nonwoven web; and, severing the threads from the springs. 